diff --git a/fluidpatcher/__init__.py b/fluidpatcher/__init__.py
index 99fbd1e..c27aa2c 100644
--- a/fluidpatcher/__init__.py
+++ b/fluidpatcher/__init__.py
@@ -461,6 +461,8 @@ def _midisignal_handler(self, sig):
                 sig.patch = -1
                 sig.val = 0
         if self.midi_callback: self.midi_callback(sig)
+        if 'patch' in sig:
+            return True
 
     def _refresh_bankfonts(self):
         sfneeded = set()
diff --git a/fluidpatcher/pfluidsynth.py b/fluidpatcher/pfluidsynth.py
index 277a80d..b05831c 100644
--- a/fluidpatcher/pfluidsynth.py
+++ b/fluidpatcher/pfluidsynth.py
@@ -626,9 +626,9 @@ def custom_midi_router(self, event):
             elif LADSPA_SUPPORT and 'ladspafx' in rule:
                 if res.ladspafx in self.ladspafx:
                     self.ladspafx[res.ladspafx].setcontrol(res.port, res.val)
-            else:
-                # not handled here, pass it to the callback
-                if self.midi_callback: self.midi_callback(res)
+            elif self.midi_callback:
+                # not handled here, pass result to the callback
+                if self.midi_callback(res): return
         if dt > 0: self.clocks = t, self.clocks[0]
         if self.midi_callback:
             # send the original event to the callback